import { ValidationMiddleware } from '../../../src/Application/Services/ValidationMiddleware';
import { Request, Response, NextFunction } from 'express';
import { ErrorResponseService } from '../../../src/Application/Services/ErrorResponseService';

jest.mock('../../../src/Application/Services/ErrorResponseService');
jest.mock('../../../src/Application/Services/Logger');

describe('ValidationMiddleware', () => {
    let req: Partial<Request>;
    let res: Partial<Response>;
    let next: NextFunction;
    
    beforeEach(() => {
        req = {
            body: {},
            params: {},
            query: {},
            path: '/test'
        };
        res = {
            status: jest.fn().mockReturnThis(),
            json: jest.fn().mockReturnThis()
        };
        next = jest.fn();
        jest.clearAllMocks();
    });
    
    describe('validateRequiredFields', () => {
        it('should pass validation when all required fields are present', () => {
            req.body = { username: 'testuser', email: 'test@example.com' };
            
            const middleware = ValidationMiddleware.validateRequiredFields(['username', 'email']);
            middleware(req as Request, res as Response, next);
            
            expect(next).toHaveBeenCalledWith();
            expect(ErrorResponseService.sendBadRequest).not.toHaveBeenCalled();
        });
        
        it('should fail validation when required fields are missing', () => {
            req.body = { username: 'testuser' }; // missing email
            
            const middleware = ValidationMiddleware.validateRequiredFields(['username', 'email']);
            middleware(req as Request, res as Response, next);
            
            expect(ErrorResponseService.sendBadRequest).toHaveBeenCalledWith(
                res,
                'Missing required fields',
                { missingFields: ['email'] }
            );
            expect(next).not.toHaveBeenCalled();
        });
        
        it('should fail validation when fields are empty strings', () => {
            req.body = { username: '', email: 'test@example.com' };
            
            const middleware = ValidationMiddleware.validateRequiredFields(['username', 'email']);
            middleware(req as Request, res as Response, next);
            
            expect(ErrorResponseService.sendBadRequest).toHaveBeenCalledWith(
                res,
                'Missing required fields',
                { missingFields: ['username'] }
            );
        });
    });
    
    describe('validateEmailFormat', () => {
        it('should pass validation for valid email', () => {
            req.body = { email: 'test@example.com' };
            
            const middleware = ValidationMiddleware.validateEmailFormat(['email']);
            middleware(req as Request, res as Response, next);
            
            expect(next).toHaveBeenCalledWith();
            expect(ErrorResponseService.sendBadRequest).not.toHaveBeenCalled();
        });
        
        it('should fail validation for invalid email', () => {
            req.body = { email: 'invalid-email' };
            
            const middleware = ValidationMiddleware.validateEmailFormat(['email']);
            middleware(req as Request, res as Response, next);
            
            expect(ErrorResponseService.sendBadRequest).toHaveBeenCalledWith(
                res,
                'Email format validation failed',
                { errors: ["Field 'email' must contain a valid email address"] }
            );
            expect(next).not.toHaveBeenCalled();
        });
    });
    
    describe('validateUUIDFormat', () => {
        it('should pass validation for valid UUID', () => {
            req.params = { userId: '123e4567-e89b-12d3-a456-426614174000' };
            
            const middleware = ValidationMiddleware.validateUUIDFormat(['userId']);
            middleware(req as Request, res as Response, next);
            
            expect(next).toHaveBeenCalledWith();
            expect(ErrorResponseService.sendBadRequest).not.toHaveBeenCalled();
        });
        
        it('should fail validation for invalid UUID', () => {
            req.params = { userId: 'invalid-uuid' };
            
            const middleware = ValidationMiddleware.validateUUIDFormat(['userId']);
            middleware(req as Request, res as Response, next);
            
            expect(ErrorResponseService.sendBadRequest).toHaveBeenCalledWith(
                res,
                'UUID format validation failed',
                { errors: ["Field 'userId' must contain a valid UUID"] }
            );
            expect(next).not.toHaveBeenCalled();
        });
    });
    
    describe('validateStringLength', () => {
        it('should pass validation for strings within length constraints', () => {
            req.body = { username: 'testuser', password: 'password123' };
            
            const middleware = ValidationMiddleware.validateStringLength({
                username: { min: 3, max: 20 },
                password: { min: 8, max: 50 }
            });
            middleware(req as Request, res as Response, next);
            
            expect(next).toHaveBeenCalledWith();
            expect(ErrorResponseService.sendBadRequest).not.toHaveBeenCalled();
        });
        
        it('should fail validation for strings that are too short', () => {
            req.body = { username: 'ab' }; // too short (min 3)
            
            const middleware = ValidationMiddleware.validateStringLength({
                username: { min: 3, max: 20 }
            });
            middleware(req as Request, res as Response, next);
            
            expect(ErrorResponseService.sendBadRequest).toHaveBeenCalledWith(
                res,
                'String length validation failed',
                { errors: ["Field 'username' must be at least 3 characters"] }
            );
        });
        
        it('should fail validation for strings that are too long', () => {
            req.body = { username: 'a'.repeat(25) }; // too long (max 20)
            
            const middleware = ValidationMiddleware.validateStringLength({
                username: { min: 3, max: 20 }
            });
            middleware(req as Request, res as Response, next);
            
            expect(ErrorResponseService.sendBadRequest).toHaveBeenCalledWith(
                res,
                'String length validation failed',
                { errors: ["Field 'username' must not exceed 20 characters"] }
            );
        });
    });
    
    describe('combine', () => {
        it('should run all validations in sequence and pass if all succeed', (done) => {
            req.body = { username: 'testuser', email: 'test@example.com' };
            
            const nextSpy = jest.fn(() => {
                try {
                    expect(nextSpy).toHaveBeenCalledWith();
                    expect(ErrorResponseService.sendBadRequest).not.toHaveBeenCalled();
                    done();
                } catch (error) {
                    done(error);
                }
            });
            
            const combinedMiddleware = ValidationMiddleware.combine([
                ValidationMiddleware.validateRequiredFields(['username', 'email']),
                ValidationMiddleware.validateEmailFormat(['email']),
                ValidationMiddleware.validateStringLength({ username: { min: 3, max: 20 } })
            ]);
            
            combinedMiddleware(req as Request, res as Response, nextSpy);
        });
        
        it('should stop at first validation failure', () => {
            req.body = { username: 'testuser' }; // missing email
            
            const combinedMiddleware = ValidationMiddleware.combine([
                ValidationMiddleware.validateRequiredFields(['username', 'email']),
                ValidationMiddleware.validateEmailFormat(['email']), // this won't run
                ValidationMiddleware.validateStringLength({ username: { min: 3, max: 20 } }) // this won't run
            ]);
            
            combinedMiddleware(req as Request, res as Response, next);
            
            expect(ErrorResponseService.sendBadRequest).toHaveBeenCalledWith(
                res,
                'Missing required fields',
                { missingFields: ['email'] }
            );
            expect(next).not.toHaveBeenCalled();
        });
    });
});